In clean rooms, such as bio clean rooms, airborne microorganism particles and non-microorganism particles are detected and recorded using particle detecting devices. See, for example, Japanese Unexamined Patent Application Publication No. 2011-83214 and N. Hasegawa, et al., Instantaneous Bioaerosol Detection Technology and Its Application, azbil Technical Review, 2-7, Yamatake Corporation, December 2009. The state of wear of the air-conditioning equipment of the clean room can be ascertained from the result of the particle detection. Moreover, a record of particle detection within the clean room may be added as reference documentation to the products manufactured within the clean room. Optical particle detecting devices draw in air from a clean room, for example, and illuminate the drawn-in air with light. If a microorganism particle or non-microorganism particle is included in the air, then the particle that is illuminated by the light will produce fluorescence or scattered light will be produced by the particle. Because of this, it is possible to detect the numbers and sizes of microorganism particles and non-microorganism particles that are included in a gas, through detecting the fluorescent and scattered light. Moreover, a technology able to detect accurately particles in not just clean rooms, but in fluids as well, is desired. See, for example, Japanese Unexamined Patent Application Publication No. H8-29331.
The intensity of fluorescence emitted from particles may differ depending on the type of particle. Moreover, the intensity of scattered light produced by a particle may also differ depending on the type of particle. Because of this, a method has been proposed for identifying whether a particle is a biologic particle or a non-biologic particle based on the intensity of fluorescence and on the intensity of scattered light. See, for example, US Patent Application Publication No. 2013/0077087.
Given this, an aspect of the present disclosure is to provide a particle detecting device and particle detecting method wherein biologic particles and non-biologic particles can be discriminated accurately.